Data processor with selectable operating modes

ABSTRACT

A word processing system incorporating a typewriter as an input/output terminal, a mass storage system such as a magnetic tape recorder/player for storing data, and a shift register connected as a buffer memory between the typewriter and the recorder/player. The system is operative in two basic modes. The first is a draft mode in which the typewriter is operable manually to write characters and generate corresponding signals which are transferred through the buffer to storage on tape or is operable in response to signals transferred from tape. The second is a final mode which differs in that there is no storage made of signals corresponding to characters written by manual manipulation of the typewriter. The system also includes skip/delete controls; a character key, a word key and a line key which, if operated when the system is in the draft mode cause deletion of the signals corresponding to the selected character, word or line from storage, and if operated when the system is in the final mode cause the typewriter to skip writing of the selected character, word or line without however altering the storage of the signals.

United States Patent [191 Heitman et a1. July 9, 1974 DATA PROCESSORWITH SELECIABLE OPERATING MODES 57] ABSTRACT [75] Inventors: Richard E.Heitman, Acton;

Richard C. Norris, Belmont, both of Mass.

[ 73] Assignee: Arthur D. Little, Inc., Cambridge.

Mass.

[22] Filed: May 18, 1972 [21] Appl. No.: 254,726

[52] US. Cl. 340/1725, 197/19 [511 Int.Cl. G06f3/10,G11b 13/00 [58]Field of Search 340/1725; 197/19, 20

[56] References Cited UNITED STATES PATENTS 3,260,340 7/1966 LOcklan cta1 197/19 3,291,277 12/1966 Borrellietal 197/20 3,297,124 1/1967 Sims197/19 3,490,004 1/1970 Ross 340/1725 3,501,747 3/1970 Bungard et a1.340/1725 3,528,063 9/1970 Kolpek 340/1725 Primary Examiner-Paul J. HenonAssistant ExaminerPaul R. Woods Attorney, Agent, or FirmSchiller 8LPandiscio A word processing system incorporating a typewriter as aninput/output terminal, a mass storage system such as a magnetic taperecorder/player for storing data, and a shift register connected as abuffer memory between the typewriter and the recorder/player. The systemis operative in two basic modes. The first is a draft mode in which thetypewriter is operable manually to write characters and generatecorresponding signals which are transferred through the buffer tostorage on tape or is operable in response to signals transferred fromtape. The second is a final mode which differs in that there is nostorage made of sig nals corresponding to characters written by manualmanipulation of the typewriter.

The system also includes skip/delete controls; a character key, a wordkey and a line key which, if operated when the system is in the draftmode cause deletion of the signals corresponding to the selectedcharacter, word or line from storage, and if operated when the system isin the final mode cause the typewriter to skip writing of the selectedcharacter, word or line without however altering the storage of thesignals.

9 Claims, 14 Drawing Figures MLHN CONTROL 54 28 22A i 5555 ADDRESS t Y ll. .I LOGIC DISDLAY 72 1 70 l l BUFFER l WRTE CONTROL CONTROL l LOGTC 75I l 50 l 52 l 64 56 TAPE l CONTROL. I asst; L 2531f T 5 l LOGlC F MEMORYMOtTrPtExm CWLUWS 1 l tNPUT/OUTPUT J 5 DATA PRINTER I I {60 STORAGE l rL PRINT L FNPUT READ J l CONTROL -3- DEMULTB- DATA LOGIC I PLFXEPCtRCUITS l I 66 l 74 63 I l L I a J t l MARGIN J READ READ J ADJUSTCONTROL ADDRESS J LOGtC LOGIC CIRCUWS PATENTED I- 91974 3.823.389

WEI 01 HF 15 FIG. I.

Pmemmm emu sum 02 ur15 PATENTED 9!!!" 3,823,389

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PATENTEII 91974 3.823.389

sum "as or 1s J C K R2 224 R MAIN 226 22 R f DATA r MU LTI- PLEXERENABLE WRITE CLOCK 232 STATE 2/2 2/7 a COUNTER READ/WRITE HEAD ENABLEREAD M CASSETTE COUNTER I 2 4 BINARYTO-OCTAL CONVERTER 5 4 3 2 I O ICCRECTIFIER AND SHAPER RECTIFIER AND SHAPER SHIFT REGISTER DEMULTI- PLEXERPATENTED 3.823.389

sum 10 or 15 FORCE SP FORCE BSP FORCE CR ENABLE GATES PRINT MODE CIM PIM

ANY FUNC- TION FROM KEYBOARD DELAY PULSES ESP ESP 2 ENABLE OPERATOR c1 TAB 5; TAB GATES A DECODEF? g TABS E TABCL TABCL g 1 1 & E R2 ENABLE R2(I R A LTJJRZA GATES 2 5 w R5 R5 6 E T1 T1 32' O T T 2 o 2 2 O F S EPARITY CHECKER PATENTED 91974 sum 11 nr 15 0 Q 71 PRINT MODE #3 5 C 6I44 30] D Q NORMAL 2oI SHIFT CRAT 8?;322 320 I/ TO TYPE IN 29885 CELL326 NORMAL INSERLO 3H CYCLE INSERT 302 MODE 3 D Q 20! SHIFT D Q R INSERTI c 6 TIR EU NCTION OVERFLOW FROM K/B 3,3

0 PIM 306 TERMINATE SHIFT 344 2? K 342 HUNTER I Q xf aaa L9 340 R 6DELETE CLEAR BUFFER F/G. l0.

PATENTEUJUL 3.823.389

MN 12 (if 15 R2 T R A- SHIFT R5 REGISTER m DEMULTI- PLEXER 2 4 46 368 8*I 262 FORWARD] L 359 I 354 370 BCD 362 I 574 COUNTER 56 47 5721i 35a 3376 I I l I /360 B K CONVERTER LO as4 ft 378/ O 77 DISPLAY fza MOTORDRIvE 366 CIRCUITS r READ/WRITE 238 M CASSETTE HEAD DATA PROCESSOR WITHSELECT ABLE OPERATING MODEQ This invention relates to data processing,recording and printing apparatus, and more particularly toelectronically controlled data recording and printing systems employinga keyboard-operated printer as in input/output terminal.

A large number of systems are known in which data entered on akeyboard-operated printer are encoded and stored on a record storagemedium, the process being reversible so that the information stored onthe record medium can be decoded and printed by the printer. It is alsoknown to record the coded data on a wide variety of recording media suchas magnetic tape or cards, punched tape and the like. The systemenjoying the widest use, perhaps due to its versatility, is the typedescribed, for example, in US. Pat. Nos. 3,297,124, 3,260,340, and2,217,!50 among many others. This latter system is particularly adaptedfor use with printers of the type disclosed in US. Pat. No. 2,919,002issued to L. E. Palmer.

The Palmer patent describes a device including a single element printinghead having all of the characters of a type font, each being positionedat a unique location on a globular surface of a single printing head.The head is mounted for movement in a path parallel to a platen whichcan only rotate in a direction perpendicular to the path of motion ofthe head. The Palmer device selects a character by tilting and rotatingthe globular element so that a selected character is positioned directlyopposite the platen, the selection of the character being responsive tothe depression of one of a plurality of keys on a keyboard.

While data processing and recording systems employing the Palmer-typeprinter have been commercially successful, it has been found that theysuffer from certain limitations. For example, in such systems, equipmentand record media are relatively quite costly. In addition, some aspectsof such systems are somewhat inconvenient to use.

This invention relates particularly to improvements in word processingsystems which lead to more efficient use of machines, such as Palmerdevices or other writing devices, magnetic data recorders and the likeassem bled for form a data processor-recorder-printer. To this end it isimportant to provide basic machine operating modes which are the mostconvenient to use in normal applications of theprocessor-recorder-printer.

Typically, known word processing systems have three basic operatingmodes. In the first or Record mode, data typed on a keyboard is recordedin a mass storage means. In the second or Play mode, data is retrievedfrom a mass storage means and can be displayed on a printer or otheroutput device. ln the third mode (Adjust), data can be retrieved anddisplayed with an automatic adjust mechanism in operation controllingthe right-hand margin of the display. These three modes are convenientin use except when data is being retrieved and edited, or otherwisemodified. On such occasions, the user must switch frequently between theRecord mode and the Play mode. When systems of the type described are inthe Play mode, it is normally permitted to type data at the keyboardwhen the system is otherwise inactive. In such cases, the typed datawill be displayed on the printer or other output device, but will not berecorded in the mass storage means.

This invention describes a word processing system with two basicoperating modes. In the first operating mode, hereinafter referred to asthe Draft" mode, data storage (recording) and data retrieval and display(writing) are both pennitted. In the second operating mode, hereinafterknown as the Final" mode, data storage is not pennitted, and datadisplay is preferably under the influence of a right-hand margin adjustmechanism. Thus in essence, the Draft mode of operation of the presentinvention combines the operations of both the Record and Play modesdescribed above in connection with a typical prior art word processingsystem. As recording and playing can both occur in the Draft modehereinafter described, data can be edited or otherwise modified withoutrequiring the user to switch between one operating mode and another.

In copending application Ser. No. 254,727 filed May 18, 1972 andassigned to the same assignee as this present application, there isdisclosed a word processing system incorporating an input/outputprinter, a buffer memory and a mass storage means. The input/outputprinter is conveniently a typewriter such as is described in US. Pat.No. 2,919,002 so that when data are retrieved from the mass storagemeans, via the buffer memory, they are displayed by being printed outlineby-line on a sheet. The word processing system described in saidcopending application permits the operator to insert new data at anypoint in a block of data retrieved from the mass storage means, and todelete (i.e., permanently to eliminate or expunge from a record ormemory) data between two points in a block of data retrieved from themass storage means. Editing changes of this nature are normally recordedin the mass storage means, but such activity is permitted only in theDraft operating mode. In particular, controls are provided which permitthe selective deletion of a character, a word, or a line, when themachine is in the Draft mode. When the above word processing system isin the Final mode of operation, the same controls provide the ability toselectively skip over a character, a word, or a line. Skipping over datadoes not involve a process of recording new data in the mass storagemeans, and can therefore be permitted in the Final mode. Skipping doesnot erase the data from the record stored in the buffer memory, or massstorage means, but simply prevents, at least at the time, the printingor display of the skipped data. In addition, it is not normally neededto skip data when operating the system in the Draft mode: thus, it isconvenient to provide the delete and skip features with a single set ofcontrols. Preferably, indication is provided to show whether operating acontrol will cause deletion or skipping of data.

Additional controls are provided to cause recorded data to be displayedor printed on the output device. In the embodiment to be described, fivesuch controls are provided: play character, play word and play linecontrols cause the next recorded character, word or line to bedisplayed; a play auto" control causes continuous playing until the endof a document or some other condition is encountered; and a stop playcontrol prevents any further data being displayed.

In the following description, it will be apparent that to play a word,for example, it is only necessary to operate the play word controlregardless of whether the word processing system is in the Draft orFinal mode.

In a typical prior art word processing system, the operator must firstplace the system in the Play mode, then select whether a character, wordor line is to be played, and finally operate a Start control.

It is an object of this invention to provide a word process-systemcomprising an input/output device and a mass storage means having twobasic operating modes. It is a further object of this invention toprovide such a system wherein the first operating mode permits therecording of data in the mass storage means, the retrieval of data fromthe mass storage means, and the display on an output device of dataretrieved from the mass storage means, and the second operating modepermits only the display of retrieved data, preferably under the controlof a right-hand margin adjust mechamsm.

It is yet another object of the invention to provide such a systemwherein a single control is used to either delete or skip a character inthe retrieved data, depending upon a selected operations mode of thesystem. Yet another object is to provide such a single control systemwherein if the system is in the first operating mode, the character canbe deleted, and in the second operating mode it will be skipped. It is afurther object of this invention to provide a like means for selectivelydeleting or skipping a word, and for deleting or skipping a line.

Other objects of the invention will in part be obvious and will in partbe apparent hereinafter.

The invention accordingly comprises the apparatus possessing theconstruction, combinations of elements, and arrangement of parts whichare exemplified in the following detailed disclosure, and the scope ofthe application of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the presentinvention, reference should be had to the following detailed descriptiontaken in connection with the accompanying drawings wherein:

FIG. I is a perspective illustration of the typewriter encoupled consoleembodying the principles of the present invention:

FIG. 2 is an enlarged view of the console of FIG. 1 showing variouscontrol buttons, displays and other elements;

FIG. 2A is a perspective view of a standard tape cassette illustratingin phantom, the organization of information on the tape according to theprinciples of the present invention;

FIG. 3 is a block diagram illustrating the organization of theinvention;

FIG. 4 is a block diagram showing details of the keyboard interfacelogic of FIG. 3',

FIG. 5 is a block diagram showing details of the buffer memory of FIG.3;

FIG. 6 is a logic diagram partly in block form illustrating a clockingcontrol system forming part of the buffer control of FIG. 3;

FIG. 7 is a logic diagram partly in block form illustrating outputmultiplexer, input demultiplexer, and read and write circuits shown inFIG. 3;

FIG. 8 is a timing diagram illustrating the operation of elements ofFIG. 7;

FIG. 9 is a logic diagram partly in block form, showing the printcontrol logic system of FIG. 3;

FIG. 10 is a diagram illustrating some logic employed in the maincontrol of FIG. 3 for controlling clocking of the buffer memory;

FIG. 11 is a diagram, partly in block form, showing address displaylogic coupled with the control console;

FIG. 12 is a diagram illustrating logic in the main control of FIG. 3;

FIG. 13 is an additional logic diagram illustrating the main control ofFIG. 3; and

FIG. 14 is a logic diagram partly in block form showing part of themargin adjust logic of FIG. 3.

To achieve the foregoing and other objects, briefly the presentinvention employs an input/output writing device, a mass storage means,and a main buffer memory, typically a shift register, for selectivelytransferring data between the writing device and the mass storage means.Means are provided for controlling the transfer of data so that thesystem operates in either the Draft or the Final mode.

The operator of the system will normally create an initial draft of adocument in the Draft mode, so that the characters making up thedocument are recorded in the mass storage means. The operator willsubsequently make any necessary editing changes or other modificationsin the same Draft mode, so that the modifications are recorded in themass storage means. In this way, the mass storage means is used toaccumulate the characters needed to display or print out an errorfreedocument. The operator will normally generate one or more final copiesof the document in the Final mode so that the right-hand adjustmechanism can compensate for any changes in recorded line length causedby the editing procedures. It is, of course, permissible for theoperator to generate a final copy of a document or part of a document inthe Draft mode. Such a procedure is preferable if the displayed lineformat is complex, as in tabular matter.

When the operator is editing a recorded document in the Draft mode, thedelete and insert features of the above word processing system willnormally be used, in addition to other procedures described in the abovementioned copending application.

The two operating modes which form a basis for this invention can bedescribed in another manner. In the Draft mode the typewriter keyboardis active. That is, any characters or typewriter functions (space,backspace, etc.) typed by the operator will be recorded in the massstorage means. In the Final mode, the keyboard is inactive. That is,data typed will not be recorded in the mass storage means, although itmay be displayed on the output device.

Referring now to the drawings, there is shown in FIG. 1 a preferredarrangement of equipment in which the invention is incorporated. Theapparatus of the invention includes an input/output printer 20interconnected by an electrically conductive cable 21 to a control console unit 22 for controlling recording, reproducing, and editing.Printer 20 typically includes a manually operable keyboard 23 forcontrolling a single head printer of the Palmer-type which has beenadapted (for example by being emplaced on a baseplate 24 which iscapable of detecting the condition of the latch and cycle shaft switchesin the printer and also having solenoids capable of driving the latchesand cycle shaft of the printer) for producing an output indicative ofthe condition of those switches. Such a baseplatc is described in U.S.Pat. Nos. 3,452,851 and 3,453,379 issued to L. Holmes, Jr. In printersof the Palmer type each character is automatically encoded when typed.When such a printer is combined with a Holmes type baseplate thecombination will be capable of translating or interconverting formationof typed characters and performance of printing functions withcorresponding coded character and function signals.

Unit 22 has a control panel 26 shown in more detail in FIG. 2, the panelincluding a spring-loaded, normally closed cassette door 27 which ismoveable so that a magnetic tape cassette 240 (shown in more detail inFIG. 2A) can be loaded into a tape transport mechanism located behindthe door. Adjacent door 27 is a display 28 for indicating a recordnumber corresponding to the position of a data location on the tape 18in a cassette 240 which may be loaded into the machine. On control panel26 are also a number of keys or buttons and display lights associatedwith data entry, editing and playback. The system of the invention isintended to have three basic operating modes, a draft mode, a final modeand an insert mode. To provide for selection of the mode of operation ofthis system there are provided a Draft button 30, a Final button 31, andan Insert button 32. To provide for control of printing out onto theprinter of a character, word, or line from storage, either while thesystem is in draft or final mode, there are included a Character button33, a Word button 34, and a Line button 35, plus an Automatic button 36for allowing the system to print continuously. An On button 37 is alsoprovided for starting the system. Stop button 38 is included forstopping any printing operation by the machine. The deleting or skippingof characters, words and lines respectively is provided by manipulationof Character, Word and Line buttons 45, 39 and 40.

A brief description of the functional consequences of the operation ofthe various buttons on control panel 26 will be helpful in understandingthe detailed structural description of the device. It is intended thatthe system be capable of both recording data onto a cassette 240 orplaying data from a cassette 240 onto printer when operating in thedraft mode. Specif- -cally, it is intended during draft mode operationthat any data entered by manipulation of keyboard 23 of printer 20should be stored in a magnetic storage or record in the system with anypreviously recorded characters being overwritten by new data beingstored at the same data locations. In order to accomplish this end oneneed merely start the system, select the record location, press Draftbutton 30 and proceed to type in data on the keyboard. To cause the datathus stored to actuate printer 20 and therefore to be typed out, it isonly necessary to return to the beginning of the stored data to pushCharacter button 33 to obtain print out of a single character, to pushWord button 34 to obtain a single word, to push Line button 35 to obtaina single line, or to push Automatic button 36 to permit the entirestored data to be reproduced on printer 20.

If one should now press Final button 31, the system is conditioned sothat no storage of data manually typed or entered on printer 20 canoccur, but that only the data stored in the machine can be played out onprinter 20. When playing in the Final mode it will be later seen that anautomatic right margin control system operates. The Draft and Finalmodes of operation are mutually exclusive and the system provides thatif either the Draft or Final buttons are pushed, the machine is switchedfrom the one to the other mode of operation.

Depression of Insert button 32 while the system is in the Final modewill be ineffective, i.e. will not in any sense allow the machine tooperate other than in normal Final Mode operation. On the other hand, ifthe In sert button 32 is depressed while the system is in the Draftmode, the system switches to an lnsert Mode of operation, and ifdesired, visual indication can be given that the machine is in an lnsertMode, as by lighting lnsert button 32 or the like. The lnsert Mode isintended to provide an operation such that data entered on printer 20 bymanual operation of the keyboard 23 will be inserted into storage, up toa limit, without overwriting or othenivise destroying previously storeddata. Only typing and recording can take place while in the Insert Modesince pushing any other buttons (except the Draft or Final buttons) onthe control panel will cause the machine to trip out of the Insert modeand revert to the Draft mode. If lnsert button 32 is pushed again, thesystem will switch out of the Insert Mode back to the Draft Mode and, ofcourse, any visual indication of lnsert Mode operation will terminate.If Final button 31 is pressed, the system will switch to Final modeoperation.

The play or print buttons 33, 34, 35, 36 or 38 control the extent towhich data will be read out of storage, either in Draft or Final modeoperation, and displayed on printer 20. Each time Character button 33 ispushed, the next character in storage will be read out on printer 20.Similarly, depression of Word button 34 or Line button 35 will cause thenext word or line in storage to be read out on the printer. When theAutomatic button 36 is pushed, the system will cause the printer 20 totype out the data in storage continuously until some stopping commandoccurs. The latter can be obtained by pressing Stop button 38, or bycertain special conditions which will be described hereinafter.

Step Right and Step Left buttons 41 and 42 control the shifting of datain storage. Each time either is pushed the data in storage is shifted byone character in the appropriate direction and the single print head 16or carrier on the printer 20 similarly steps. In this respect buttons 41and 42 actuate the print head [6 to move in the same manner as the spacebar and backspace key on the printer keyboard 23, with certainexceptions as will be explained later. Preferably, if one of the buttons41 and 42 is held down, repetitive action is initiated so that thesystem steps sequentially character by character.

As described, there are three delete/skip buttons 45, 39 and 40. Whenthe system is in Draft mode depression of these buttons will serve todelete a recorded character, word or line from storage. When the systeminstead is in the Final mode, these buttons act as skip buttons whichcause the system to skip the appropriate character, word or line instorage without overwriting or otherwise destroying the skipped data.Because the functioning of these buttons to cause either deletion orskipping depends upon the mode in which the system is then operating,means are provided in the form of visual indicating lights 43 and 44which respectively light up to indicate the nature of the function ofthe buttons, i.e. delete or skip as the case may be.

There are two buttons for controlling tape motion, a Tape Forward button46 and a Tape Back button 47. These are preferably of the spring-loadedtype and each has a first or up position and a second or down position.Pushing either of the tape buttons 46 or 47 to its down position causesthe system to move the tape 18 either back or forward (as the case maybe) to the be ginning of the next of a number of predetermined datablocks 19 or stations on the tape 18. This motion from predeterminedstation to predetermined station on the tape 18 will continue as asmooth sequence until the appropriate button is released. After releaseof the button, the motion of the tape 18 in the cassette 240 willcontinue until the next predetermined station on the tape 18 is reached,at which time the motion of the tape 18 is stopped. Similarly pushingeither buttons 46 or 47 to their up position causes the system to shiftto a fast forward or fast rewind movement (as the case may be) duringwhich the tape winds continuously. Fast winding due to pushing the TapeBack button 47 to its up position will continue until the button 47 isreleased, at which point the system then shifts to slow forward speedand continues to move the tape until the next predetermined station onthe tape is located. A similar operation in the opposite direction iseffected by manipulation of the Tape Forward button.

In the preferred embodiment the cassette tape is at least a two track(25 and 29) tape, and two read/write heads, one for each of tracks 25and 29, (or a single two-channel head such as head 238) are incorporatedinto the system. One of the tracks, 25, of the tape is for the data tobe stored. The other tape track 29 is intended to contain data addresses48, preferably in the form of coded conversions of sequentially numberedthree decimal digits, each data address 48 being physically locatedsubstantially adjacent the beginning of a data block l9 on track 25.Thus, when the tape is moved either forward or back in the cassette,circuitry associated with the address read/write head and the recordnumber display 28 will cause the latter to be appropriately indexed eachtime an address corresponding to a data block 19 or record moves pastthe read head. lf desired, one can provide an erase mechanism associatedwith the tape transport mechanism and the control panel so as to eraseselectively all data from the tape 18, and also if desired to regeneratethe addresses on the tape 18.

Also in the preferred embodiment, associated with the control panel area number of visual indicators or special lights 49 in addition to thedelete/skip light and insert indicator light discussed earlier. Theseadditional lights will be described later hereinafter. Similarly, anumber of audio signal devices to indicate certain conditions of theapparatus can also be provided and will be described hereinafter.

The operation of the device thus described can be advantageouslydescribed in connection with a typewriter as an example of the printer.There are three basic situations to be described:

I. Basic entering of data through the typewriter keyboard, i.e.recording an initial draft;

2. Insertion, deletion and other operations made on data after entry ofthe latter, i.e. editing; and

3'. Data retrieval, i.e. typing of final copy.

in order to record data initially, the operator will first activate thetypewriter and also will depress button 37 to turn on the remainder ofthe system. The operator should first set margins and tabs on thetypewriter as desired although one or more embodiments of the inventionmay include the ability to set and clear tabs on the basis of priorstored information. Then a magnetic tape cassette 240 is placed in thecarrier behind door 27 and the operator then depresses button 30 toplace the system in the draft mode of operation. The position of thetape 18 in the cassette 240 will be indicated by the address displayedat display 28. If the cassette 240 is not rewound and it is desired tostart from the beginning of the cassette, the latter can be rewound bypushing Tape Back button 47 to its up position and waiting until rewindis completed. lf the operator wishes to start beyond previously recordedmaterial that is to be preserved, the tape 18 can be moved with buttons46 and 47 until the appropriate address is noticed at display 28.

Hereafter, recording in the Draft mode is accomplished automaticallymerely by typing the desired information on the typewriter keyboard 23.Each time the operator types a Carrier Return, the data associated withthe preceding typed line is then transferred from the buffer memory ofthe system onto magnetic tape 18. If the operator observes that a wrongkey has been struck, correction can be made by depressing the Step Leftbutton 42 which causes the typewriter to automatically backspace. Whenthe typewriter has been backspaced to the error, the operator can strikeover the error with the correct character key. To get back to the pointwhere recording has been interrupted, the Step Right button 41 can bedepressed, or as will appear later, one can play out the interveningmaterial which has been recorded, or lastly one can retype theintervening material and rerecord it.

If the operator wishes to underscore a word upon entry, the word can betyped and then, using the regular backspace key on the typewriterkeyboard which will provide a recorded backspace, the typewriter shouldbe backed up to the beginning of the word. The word can then beunderscored, the underscoring being recorded also.

When the operator has completed the draft, a Stop Code should beentered. The Stop Code is generated by depressing the shift key andstriking Stop button 38 on the control panel.

Editing of a draft can be done in three basic ways:

l. A new draft can be generated in the Draft mode of operation,combining the desired parts of the old draft with typed and recordedcorrections;

2. Only specific lines requiring editing can be modifled; or

3. A final copy can be generated in the Final mode of operation withcorrections being entered on the copy as the document is printed,without recording the corrections.

Normally, the first approach would be used especially if further authorrevisions are anticipated. The third approach is appropriate if onlyfinal, minor corrections are to be made and a final copy is desired.

In generating a new draft, the following situations are likely to beencountered. First, one can edit simple typographical errors by playingback the tape 18 in the Draft mode, by first striking any one of buttons33, 34, 35 or 36. This will cause the material recorded on the cassetteto be played back on the typewriter, assuming of course that thecassette 240 has been rewound to the appropriate starting position. Thematerial is then played up to but not through the error and the error iscorrected by overstriking. Overstriking using the keyboard 23 willautomatically erase the erroneous material in the appropriate place.

1. Data recording and printing apparatus comprising in combination:input/output writing means for writing characters and for generatingcoded signals corresponding to said characters, said writing meansincluding a manually operable keyboard for initiating said writing ofcharacters and said generating of corresponding coded signals, and meansfor operating said writing means in response to coded signals to providewriting of characters independently of said keyboard; mass storage meanscoupled to said writing means for receiving, storing and returning codedsignals; means for controlling transfer of coded signals between saidwriting means and said mass storage means, and including selectivelyoperable means for initiating transfer of coded signals from said massstorage means to said means for operating so as to cause said writingmeans to write characters corresponding to the coded signals transferredfrom said mass storage means to said means for operating and; means foroperating the other aforesaid means in a first mode wherein manipulationof said keyboard causes said writing means to write characters andgenerate signals which are transferred to said storage or alternativelymanipulation of said means for initiating transfer causes coded signalsto be transferred from said mass storage means and written ascorresponding characters by said writing means, means for operating saidother aforesaid means in a second mode wherein manipulation of saidkeyboard causes said writing means to write characters but the transferof said corresponding coded signals to said mass storage means isblocked or alternatively manipulation of said means for initiatingtransfer causes coded signals to be transferred from said storage meansand written as corresponding characters by said writing means, and modeselecting means for mutually exclusively selecting between operation ofsaid other aforesaid means in either said first or said second mode. 2.Apparatus according to claim 1 wherein said means for controllingtransfer includes a buffer memory for temporarily storing andselectively transferring signals between said writing means and saidmass storage means.
 3. Apparatus according to claim 2 wherein saidwriting means is adapted to form said characters on a record medium inline of characters and line-by-line format, anD including: means fordetermining the predetermined respective characters to which signalsstored in said buffer memory, and means for controlling said writingmeans when said apparatus is in said second mode and said coded signalsare being transferred from said storage means to said writing means, soas to compel said writing means alternatively to commence a new line ofcharacters when signals corresponding to said respective characters arefound at said positions, or to stop operation of said writing means whensaid signals corresponding to said respective characters are not foundin said positions.
 4. Apparatus according to claim 2 wherein saidwriting means comprises a typewriter.
 5. Apparatus according to claim 2wherein said mass storage means comprises a magnetic taperecorder/player.
 6. Apparatus according to claim 1 wherein said writingmeans is adapted to form said characters on a record medium in a line ofcharacters and line-by-line format, and said apparatus includes first,second and third controls, selectively and mutually exclusively operablewhen said apparatus is in said first mode, for expunging respectivelyfrom storage a single selected signal corresponding to one character, aselected sequence of signals corresponding to a word, and a selectedseries of signals corresponding to an entire line of words.
 7. Apparatusaccording to claim 6 wherein said first, second and third controls aremutually exclusively operable, when said apparatus is in said secondmode, for preventing transfer of coded signals to said means foroperating said writing means so that respectively said writing meansskips writing a character corresponding to a single selected signal,skips writing a word corresponding to a selected sequence of signals,and skips writing an entire line of words corresponding to a selectedseries of signals.
 8. Apparatus according to claim 7 wherein each ofsaid first, second and third controls comprises a manually operable key.9. Apparatus according to claim 7 including means for indicating if saidcontrols are operable in either said first or said second mode.